| 摘要 |
PURPOSE: To prevent scattered toner from being accumulated on an electrifier and prevent the deterioration of image quality by driving a ventilating means at a low-speed drive quantity in the time zone affecting the image formation, and driving the ventilating means with a drive quantity which is high in speed in the other time zone. CONSTITUTION: An exhaust fan 18 is driven the first low-speed drive quantity in the time zone affecting the image formation, and the exhaust fan 18 is driven at the second high-speed drive quantity in the other time zone. A controller 23 controlling the image formation action changes the frequency of the electric power fed to the exhaust fan 18 via an inverter 24 to change the revolving speed of the exhaust fan 18 and change the air quantity, and the first low-frequency drive quantity and the second high-frequency drive quantity are applied to the exhaust fan 18. The toner scattered in an image forming device and unable to be sufficiently exhausted by an air current when the exhaust fan 18 is driven at the first drive quantity during copying is sufficiently discharged when the exhaust fan 18 is driven at the second drive quantity after copying. |
